It kind of depends on what it's used for. I picked the 870 because of it's versatility, but the 1300's a good gun too. My pick is actually not on the list...the new Benelli Nova.
I'm with duckbill, I like the benelli nova. Never had any problems with mine. I hunt with a couple of guys who use a Mossberg and I think they should be banned from a duck blind, too elmoelmoelmoelmo loud.
Tried and true. Very tight mechanism. Want fail you in the field, but all of the others will be fine too I'm sure. Look at the Beneli Nova also, but the kick like a mule.
The first gun I ever bought in my life, paid for with my own money I earned working odd jobs in 8th grade, was the winchester pump in 20 guage. It has proven to a be a great and reliable gun and has always been one of my favorites. I wouldn't trade it for the world and really look forward to passing it on to my son when he is ready!!!!
There is so much in the after market accessories for it from home defense, turkey, waterfowl, deer, dove and a whole lot more. If you chose the 870 you can get one gun that can do it all. Of course go ahead a get one of each type 870.
My wife already bought me the Beneli Nova. I added the 14oz mercury recoil reducer & a Kicks .655 extended choke for turkey and its sweet! turkey loads are always tough but dove loads are nothing.
Take it from someone whom has been into custom shotgun work for well over 20 years
without a doubt the Remington 870 is the one to own !!!!!
the only gun that has rivaled it's reliability in the field is the older model 12 Winchesters
as to the others mentioned ?
let's just say that in my 20+ years of working on shotguns that they have had the most broken parts or non functioning actions brought into the shop
i have killed turks with all these guns --I chose the chester but which ever i could grab 1st and stuff 3 shells in would be fine with me there all equal rough and tuff ss